"Own worst enemy" might have been coined for John Mayer, who's sold 20m albums and won multiple Grammys, but has turned himself into tabloid catnip by giving indiscreet interviews about his high-profile girlfriends. Even his current flame gets the innuendo treatment in the album credits, which say: "Thank you in so many ways, Katy Perry." This hasn't stopped Perry from dueting with Mayer on Who You Love, a country-pop amble that's entirely self-serving. She is a drowsy, rootsy presence, claiming: "Some have said his heart's too hard to hold/ You should see him when he shines", while Mayer murmurs his agreement. Elsewhere, the tender vocals contributed to Wildfire by surprise guest Frank Ocean are easily the most striking 85 seconds on the record. But the biggest talking point here will be Paper Doll. Apparently aimed at another ex, Taylor Swift, it's a washed-out ballad that takes the concept of "too much information" to a new level: "Strapped into heels that hurt," he mumbles, "You should have kept my undershirt." Thanks for that.